Search: id:A157659 Results 1-1 of 1 results found. %I A157659 %S A157659 99,398,897,1596,2495,3594,4893,6392,8091,9990,12089,14388,16887,19586, %T A157659 22485,25584,28883,32382,36081,39980,44079,48378,52877,57576,62475, %U A157659 67574,72873,78372,84071,89970,96069,102368,108867,115566,122465,129564 %N A157659 a(n)=100*n^2-n (n>0) %C A157659 If A=[A157659] 100*n.^2-n (99, 398, 897, 1596 ,..,); Y=[A157660] 8000*n-40 (7960, 15960, 23960..,); X=[A157661] 80000*n^2-800*n+1 (79201, 318401, 717601,.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 79201^2-99*7960^2=1; 318401^2-398*15960^2=1; 717601^2-897*23960^2=1. %C A157659 If A=[A157659] 100*n.^2-n (99, 398, 897, ,.,); Y=[A010859] 20 (20, 20, 20,. ,.,); X=[A157955] 200*n-1 (199, 399, 599,. .,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 199^2-99 *20^2=1; 399^2-398*20^2=1; 599^2-897*20^2=1. [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 10 2009] %H A157659 Wolfram MathWorld, Pell Equation %H A157659 Philippe Chevanne, Pell Equation %H A157659 Vincenzo Librandi, X^2-AY^2=1 %F A157659 a(n)=100*n^2-n (n>0) %e A157659 For n=1, a(1)=99; n=2, a(2)=398; n=3, a(3)=897 %Y A157659 Cf. A157660, A157661 %Y A157659 Cf. A010859, A157955 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 10 2009] %Y A157659 Sequence in context: A008882 A156757 A027579 this_sequence A154359 A061366 A135219 %Y A157659 Adjacent sequences: A157656 A157657 A157658 this_sequence A157660 A157661 A157662 %K A157659 nonn %O A157659 1,1 %A A157659 Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 04 2009 Search completed in 0.001 seconds